新型药物缓释功能复合支架用于结直肠癌的高效治疗及机理研究

Colon and rectal cancers (CRC) is one of the most serious cancers in terms of both incidence and mortality globally. In clinical, stents combining radio-chemotherapy have been widely used for colorectal cancer patients with advanced disease and in poor general health. However, conventional stents only play mechanical expansion and temporary treatment, and postoperative complications and in-stents restenosis caused by tumour ingrowth are major problems for patients undergoing stent displacement. Objective of the present project is to develop a novel composite intestinal stent with drug delivery function. The advantages of the stent are with both a lumen restoring capability, a sustainable intraluminal anti-tumour capability and minimal side effect. The present project will develop a double-layered silk fibroin-based intestinal stent; the inner layer is a tubular stent knitted by a tubular weft-knitting machine using polydioxanone (PDO) monofilament; the outer layer is an electrospun nano-fibrous silk fibroin (SF) membrane loaded with dual anticancer drugs of 5-fluorouracil (5-Fu) and Curcumin; the secondary structure, mechanical properties, degradation behavior, drug release property in vitro and their mechanisms of the drug-loaded SF membranes will be examined; the safety, antitumor activity and impact factors will be accessed using colorectal cancer cells HCT-116 in vitro; their mechanism will be identified in vitro and in vivo using a human colorectal cancer cell line HCT-116 and tumour-bearing BALB/c nude mice.

结直肠癌是当今全球发病率和死亡率最高的疾病之一。临床上，针对无法直接手术切除的进展期结直肠癌患者，常采用支架配合化疗等辅助方法进行姑息治疗。传统支架的缺点是仅起到肠道扩张和姑息治疗作用、术后并发症和再狭窄率高。本项目将研究一种新型药物缓释复合肠道支架，其优点是既能扩张和恢复肠道功能，又能降解和释放药物，高效靶向治疗肿瘤，副作用小。研究内容：制备一种丝素蛋白基药物缓释复合肠道支架，内层为采用纬编方法制备的聚二氧六环酮（PDO）可降解支架，外层为采用高压静电纺丝方法制备的丝素蛋白搭载5-氟尿嘧啶（5-Fu）和姜黄素药物纳米纤维膜；研究支架药膜的二级结构、力学性能、药物缓释特征、降解行为和影响机制；采用结直肠肿瘤细胞HCT-116和BALB/c裸鼠皮下诱导结直肠肿瘤模型，从细胞和动物水平，验证复合支架药膜中的丝素蛋白搭载5-Fu和姜黄素双药的安全性和结直肠肿瘤抑制效果，并明确其中的作用机理。

结直肠癌是当今全球发病率和死亡率最高的疾病之一。临床上，针对无法直接手术切除的进展期结直肠癌患者，常采用支架配合化疗等辅助方法进行姑息治疗。传统支架的缺点是仅起到肠道扩张和姑息治疗作用、术后并发症和再狭窄率高。本项目将研究一种新型药物缓释复合肠道支架，其优点是既能扩张和恢复肠道功能，又能降解和释放药物，高效靶向治疗肿瘤，副作用小。研究内容：制备一种丝素蛋白基药物缓释复合肠道支架，内层为采用纬编方法制备的聚二氧六环酮（PDO）可降解支架，外层为采用高压静电纺丝方法制备的丝素蛋白搭载5-氟尿嘧啶（5-Fu）和姜黄素药物纳米纤维膜；研究支架药膜的二级结构、力学性能、药物缓释特征、降解行为和影响机制；采用结直肠肿瘤细胞HCT-116和BALB/c裸鼠皮下诱导结直肠肿瘤模型，从细胞和动物水平，验证复合支架药膜中的丝素蛋白搭载5-Fu和姜黄素双药的安全性和结直肠肿瘤抑制效果，并明确其中的作用机理。最终研制出一种新型药物缓释复合肠道支架，支架径向支撑力在30-240cN，纵向拉伸强力大于20MPa，横向拉伸强力大于10MPa。缓释药物长达400小时以上，丝素搭载5-FU和姜黄素的联合抗肿瘤作用明显增强。免疫组织化学染色及Western blot结果显示搭载CUR与5-FU的纤维膜（0.3/0.5%）会显著提升对Stat-3、NF-κB（P-65）蛋白表达的抑制，尤其对前者抑制情况明显。抗肿瘤效果明显高于腹腔注射CUR（LD50浓度组）与5-FU（LD50浓度组）。通过本项目的实施，形成了具有自主知识产权的多项创新成果，填补了国内该技术领域的空白，促进了生物材料、纺织工程和医学临床应用的多学科交叉渗透，促进了国家医用纺织产业的发展，具有重要研究价值和意义。